Copolymers of sodium 2-acrylamido-2-methylpropanesulfonate for the production of gel-forming compositions

Abstract

Copolymers of sodium 2-acrylamido-2-methylpropanesulfonate with acrylamide, methacrylamide, sodium acrylate and sodium methacrylate have been synthesized. The influence of the chemical structure of acrylic and methacrylic acid derivatives on the copolymer's unit ratio, chain length, interaction with polyvalent metal salts, formation of polyelectrolyte hydrogels and thermo-oxidative stability of copolymers has been established. The molar ratios of units in copolymers were determined based on the composition of the initial monomer mixture. The relative activities of monomers in the copolymerization reaction of sodium 2-acrylamido-2-methylpropanesulfonate with methacrylic acid derivatives were calculated. Copolymerization of sodium 2-acrylamido-2-methylpropanesulfonate with acrylamide, methacrylamide and sodium acrylate leads to depletion, and with sodium methacrylate – to enrichment of the copolymers with sodium 2-acrylamido-2-methylpropanesulfonate units. The chain links are statistically distributed in all copolymers. The longest chains are formed as a result of copolymerization with acrylamide, while the shortest chains are obtained with methacrylamide. The formation of polyelectrolyte hydrogels from salts of polyvalent metals is achieved by the interaction of copolymer solutions with chromium and aluminum triacetate. It has been shown that, along with sulfonated polyacrylamide, copolymers of sodium 2-acrylamido-2-methylpropanesulfonate with sodium methacrylate have the potential to be used in high-temperature oil reservoirs in the oil-producing industry. The thermal-oxidative stability of the copolymer does not lead to its decomposition at reservoir temperature